1. Field of the Invention
The invention relates generally to improvements in electrical power systems, and more particularly, but not by way of limitation, to a rechargeable electrical power system providing selectable voltages.
2. Description of the Prior Art
The choice of power systems for use in marine applications has been very limited in the past. Since the market potential for batteries and other energy sources in this country, and abroad, has been largely in the field of land transportation, the fisherman found that automobile related technology crept over into and dominated his design choices.
Automobile type 12 volt electrical power systems are practically the only systems commercially available for the range of fishing craft of all but the self supporting professionals, and certainly this is true for game fishermen. In fact, larger in-board power craft mostly use the automobile type internal combustion engines, and these are almost always equipped with a 12 volt electrical system. A game fisherman often has a gasoline powered engine or the like to move his marine craft for long distances around a lake area, but he often also has an array of implements that utilize electrical power, such as a troll motor. Also the use of electric motors for prime movers of fishing craft has long been known, and in recent times, there is an increasing trend toward the use of a total electric system for powering small fishing craft.
In any event, whether the marine electrical system is a prime source for motive power, or whether the electrical power source is used principally for trolling, there is increasing usage of electric motors in the marine environment. Many fisherman have found that more satisfactory power utilization is achieved at a higher voltage than that of the standard 12 volt system, and they have combined two or more batteries in series to obtain multiples of the 12 volts obtained from standard batteries. Manufacturers are now offering 24 volt motors, and many are offering combination 12 or 24 volt motors. With the combination 12-24 volt motors, the 24 volt system can be used for moving quickly from one location to another or to move through rough water. A switch is normally provided to switch over to the more economical 12 volt system when precision or long sustained boat maneuvering is required.
Even though such 24 volt motors are available, they are most likely to be powered by the use of plural 12 volt batteries. As these battery systems are used, the problem of charging them arises and this must be accomplished by utilizing 12 volt battery chargers, since 24 volt chargers are not usually available--a further evidence of dependency on the 12 volt standard. And while it is possible to physically disconnect the combined batteries to use one or more 12 volt battery chargers, this is a costly and time consuming process requiring a considerable amount of labor and bother. This is especially true for a game fisherman who has consumed all of the daylight hours on the lake, and must replenish his energy cells during the nocturnal hours, and who himself must arise replenished for the next day of fishing.
One often overlooked aspect of marine electrical systems is that of safely recharging chemical energy cells which are often located in the proximity of gasoline bearing compartments. It is desirable that spark producing acts be carried on remotely to the site of such energy cells, as accumulations of explosive gases, especially during recharging, has led to fires and explosions resulting from sparks emitted during physical hook ups of terminal cables or from battery chargers themselves. The present invention provides an electrical power system that practically eliminates such danger.